Index: octave-3.2.4/configure
===================================================================
--- octave-3.2.4.orig/configure	2011-01-02 15:14:21.000000000 +0100
+++ octave-3.2.4/configure	2011-01-02 15:14:32.000000000 +0100
@@ -6892,7 +6892,7 @@
 $as_echo "libraries $x_libraries, headers $x_includes" >&6; }
 fi
 
-if test "$have_x"; then
+if test "$have_x" = "yes"; then
 
 $as_echo "#define HAVE_X_WINDOWS 1" >>confdefs.h
 
Index: octave-3.2.4/configure.in
===================================================================
--- octave-3.2.4.orig/configure.in	2011-01-02 15:14:20.000000000 +0100
+++ octave-3.2.4/configure.in	2011-01-02 15:14:25.000000000 +0100
@@ -258,7 +258,7 @@
 ACX_PTHREAD
 
 AC_PATH_X
-if test "$have_x"; then
+if test "$have_x" = "yes"; then
   AC_DEFINE(HAVE_X_WINDOWS, 1, [Define if you have X11])
 
   if test "$x_includes" != "NONE"; then